Show-Me State Times

University of Missouri scientists are addressing the emerging threat of nanoplastics, which are much smaller than the diameter of a human hair and invisible to the naked eye. These particles have been linked to cardiovascular and respiratory diseases in humans and continue to accumulate unnoticed in bodies of water worldwide. The challenge is to develop a cost-effective method for removing these contaminants while leaving clean water behind.

Researchers at Mizzou have recently created a liquid-based solution that eliminates more than 98% of these microscopic plastic particles from water. "Nanoplastics can disrupt aquatic ecosystems and enter the food chain, posing risks to both wildlife and humans," said Piyuni Ishtaweera, who led the study while earning her doctorate in nano and materials chemistry at Mizzou. "In layman’s terms, we’re developing better ways to remove contaminants such as nanoplastics from water."

The innovative method employs water-repelling solvents made from natural ingredients, offering a practical solution to nanoplastic pollution and paving the way for further research in advanced water purification technologies. "Our strategy uses a small amount of designer solvent to absorb plastic particles from a large volume of water," said Gary Baker, an associate professor in Mizzou’s Department of Chemistry and the study’s corresponding author. He added that future work aims to determine the maximum capacity of these solvents and explore methods for recycling them for multiple uses.

Initially, the solvent sits on the water’s surface like oil. Once mixed with water and allowed to reseparate, it floats back up carrying nanoplastics within its molecular structure. In lab tests, researchers used a pipette to remove this nanoplastic-laden solvent, leaving behind clean water. Future studies will focus on scaling up this process for application in larger bodies of water such as lakes and oceans.

Ishtaweera, now working at the U.S. Food and Drug Administration in St. Louis, noted that this new method is effective in both fresh and saltwater environments. "These solvents are made from safe, non-toxic components, and their ability to repel water prevents additional contamination of water sources," she said. "From a scientific perspective, creating effective removal methods fosters innovation in filtration technologies, provides insights into nanomaterial behavior and supports informed environmental policies."

The Mizzou team tested five different sizes of polystyrene-based nanoplastics commonly found in products like Styrofoam cups. Their results outperformed previous studies focusing on single-size plastic particles.

"Nanoplastics extraction from water by hydrophobic deep eutectic solvents" was published recently with additional co-authors Collen Ray, Wyland Filley, and Garrett Cobb contributing.